1. Field of the Invention
The invention relates to an arrangement for keeping a floating body spaced from a mother vessel, which floating body is intended for use during borehole-seismic measurements for supporting the seismic equipment and comprises at least two buoyant bodies connected by means of a rigid framework construction.
2. Description of the Prior Art
A floating body of this type is disclosed in Norwegian Patent Application No. 84 3010, filed July 25, 1984, corresponding to U.S. patent application Ser. No. 758,740, filed July 25, 1985, now U.S. Pat. No. 4,660,174. The device described in this known publication consists of two buoyancy bodies which are rigidly connected by means of a steel framework construction. Below each buoyant body a seismic signal transmitter, preferably an air gun of known type is suspended. The above mentioned publication relates to apparatus used for raising these air guns to a position directly under the buoyant bodies when the floating body is taken on board a ship. The floating body will be maintained in a correct position in relation to the borehole which is to be analyzed by suspending it from a crane or boom extending from a vessel.
During use of this type of apparatus some problems have arisen, as the floating bodies can move too close to the ship's side and possibly strike against it, caused by drift or waves in the sea. Such changes in position and impact are very disadvantageous and can adversely influence the emission of signals or make such emission impossible, with the result that it will be necessary to stop the measurements and wait for more favorable conditions.